/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.apache.coyote.http11.filters;

import org.apache.coyote.InputBuffer;
import org.apache.coyote.http11.InputFilter;
import org.apache.tomcat.util.buf.ByteChunk;

import java.io.IOException;

/**
 * Input filter responsible for replaying the request body when restoring the
 * saved request after FORM authentication.
 */
public class SavedRequestInputFilter implements InputFilter {

	/**
	 * The original request body.
	 */
	protected ByteChunk input = null;

	/**
	 * Create a new SavedRequestInputFilter.
	 *
	 * @param input The saved request body to be replayed.
	 */
	public SavedRequestInputFilter(ByteChunk input) {
		this.input = input;
	}

	/**
	 * Read bytes.
	 */
	@Override
	public int doRead(ByteChunk chunk, org.apache.coyote.Request request)
			throws IOException {
		int writeLength = 0;

		if (chunk.getLimit() > 0 && chunk.getLimit() < input.getLength()) {
			writeLength = chunk.getLimit();
		} else {
			writeLength = input.getLength();
		}

		if (input.getOffset() >= input.getEnd())
			return -1;

		input.substract(chunk.getBuffer(), 0, writeLength);
		chunk.setOffset(0);
		chunk.setEnd(writeLength);

		return writeLength;
	}

	/**
	 * Set the content length on the request.
	 */
	@Override
	public void setRequest(org.apache.coyote.Request request) {
		request.setContentLength(input.getLength());
	}

	/**
	 * Make the filter ready to process the next request.
	 */
	@Override
	public void recycle() {
		input = null;
	}

	/**
	 * Return the name of the associated encoding; here, the value is null.
	 */
	@Override
	public ByteChunk getEncodingName() {
		return null;
	}

	/**
	 * Set the next buffer in the filter pipeline (has no effect).
	 */
	@Override
	public void setBuffer(InputBuffer buffer) {
		// NOOP since this filter will be providing the request body
	}

	/**
	 * Amount of bytes still available in a buffer.
	 */
	@Override
	public int available() {
		return input.getLength();
	}

	/**
	 * End the current request (has no effect).
	 */
	@Override
	public long end() throws IOException {
		return 0;
	}

}
